The present invention relates to an obstacle detecting control device of a vehicle that comprises a radar device to detect an obstacle in front of the vehicle.
Conventionally, an obstacle detecting control device of a vehicle that detects an obstacle with a radar device is known. Some type of such obstacle detecting control device comprises a yaw-rate detection sensor to detect a yaw rate of the vehicle, a steering-angle sensor to detect a steering angle of a steering wheel of the vehicle, or the like, to detect a turning radius of the traveling vehicle based on detection values of such sensors, and thereby predicts a traveling path of the vehicle (a radius of curvature of a traveling-path center line) based on the detected turning radius of the traveling vehicle (Japanese Patent Laid-Open Publication No. 7-215147, U.S. Pat. No. 5,689,264, for example). Herein, a position of the detected obstacle at the time a specified period of time (a radar scanning time) has lapsed is predicted based on the predicted traveling path, and determination as to whether or not an obstacle that is detected at the time the specified period of time has lapsed after the detection of the obstacle is identical to the above-described obstacle whose position has been predicted is made based on the above-described position prediction. A device disclosed in the above-described US patent is also capable of continuing pursuit of the obstacle with the above-described positron prediction even if the detection of obstacle is failed temporarily.
Herein, the above-described position prediction of the obstacle could be easier by calculating an offset distance of the obstacle from a center line of the predicted traveling path at the time the obstacle is detected and by using this calculated offset distance in a case where the detected obstacle is a stationary obstacle (a relative speed of the obstacle with respect to the vehicle may be detected by the radar device, and it may be determined based on this relative speed and a traveling speed of the vehicle whether the detected obstacle is the stationary one or not, for example). Namely, since in general the radius of curvature of the traveling-path center line (turning radius of the traveling vehicle) may not change so greatly during the traveling of the vehicle, the position of the stationary obstacle could be predicted easily by assuming that the above-described offset distance of the stationary obstacle from the center line of the predicted traveling path does not change during the above-described specified period of time. Determination as to whether the traveling vehicle hits the obstacle or not may be also made easily based on the amount of the offset distance.
However, in fact, there exists a traveling road with a curve that changes the radius of curvature of the traveling-path center line (turning radius of the traveling vehicle) so quickly during the specified period of traveling time (especially, at around an exist or entrance portion of a corner of the curving road). Thus, when the vehicle travels on this kind of curving road, there is a problem in that the obstacle's position could not be predicted accurately.